small population - Post Questions and Discuss Biostatistics Programs and Stastistical Analysis Questions

Dear All,
I have a little problem in evaluating the statistical significance of different parameters in a small population subjected to a treatment. Normally I use paired T-Test but in this case the population is so small (n=12) that I suspected the method is not accurate enough. Are ther other statistical test or corrections for for small population one can adopt?
thanks for the help